JUST WATCHED

Sloane Stephens wins US Open

MUST WATCH

Story highlights

This was the seventh time in the Open Era two first-time finalists faced off in a grand slam final

(CNN)Sloane Stephens' epic comeback is complete.

Stephens, who has jumped more than 900 spots in the world rankings in a month, is now a grand slam champion, winning the US Open 6-3, 6-0 against No. 15 seed and fellow American Madison Keys at Arthur Ashe Stadium in Flushing, New York.

This was only the seventh time in the Open Era, and the second time at the US Open, that two first-time finalists have faced off in a grand slam final. This also was the first all-American US Open final since 2002, when Serena Williams defeated Venus Williams. Stephens is the first American woman other than the Williams sisters to win a grand slam title in 15 years.

The 24-year-old Stephens, unseeded and ranked 83rd, is the third player to win the US Open ranked outside the top 10 since computer rankings began in November 1975. The others were unranked Kim Clijsters in 2009 and No. 26 Flavia Pennetta in 2015.

When it was over, the two Americans shared a long embrace on the court. After Stephens celebrated with her support group, including her mother, Sybil Smith, she returned to the court and sat next to Keys, whom Stephens calls her best friend on the WTA tour.

Read More

"Honestly I wouldn't have wanted to play anyone else," Stephens said. "For us both to be here is such a special moment. I told her I wish there could be a draw, because I wish we could have both won. I think that if it was the other way around she would do the same for me. I'm going to support her no matter what, and I know she's going to support me no matter what. To stand with her today is incredible. That's what real friendship is."

Stephens with Madison Keys after the match.

None of this looked possible earlier this summer.

Stephens, who had been sidelined for 11 months after a foot injury and underwent surgery in January, made her comeback at Wimbledon and entered this summer's US Open Series ranked 957th. But she's been on a tear in the North American events, reaching the semifinals in Toronto and Cincinnati.

"I had surgery January 23," Stephens said. "If someone told me then that I'd win the US Open, 'It's impossible,' I would say. 'It's absolutely impossible.' My journey to get here, coming back, just being able to keep it all together and have such a great team behind me -- this journey's been incredible. And I honestly wouldn't change it for the world."

With the win, Stephens is projected to rise to No. 17. She also nets a hefty payday: $3.7 million. Her career earnings heading into this tournament were $4,519,709, with $310,546 coming this year.

"That's a lot of money," a visibly surprised Stephens said, as Keys jokingly tried to take the check.

Keys, 22, is projected to move up to No. 12 by reaching the final.

"Sloane is truly one of my favorite people, and to get to play her was really special," Keys said. "Obviously, I didn't play my best tennis today and was disappointed, but Sloane, being the great friend that she was, was very supportive. If there's someone I have to lose to today, I'm glad it's her."

An improbable run

Stephens, who started playing tennis at age 9, comes from an athletic family. Her mother, Smith, is a former collegiate swimmer at Boston University. Her late father, John Stephens, was an NFL running back in the late 1980s and early 1990s.

Stephens made her breakthrough in 2013 when she defeated Serena Williams to reach the Australian Open semifinal. She would go on to lose to eventual champion Victoria Azarenka.

Her first singles title was in 2015 in Washington. She added three more titles in 2016.

The potential has been there for her to win a grand slam, but what she's done this summer, considering the circumstances with her previous injury, is shocking.

Heading into Saturday's final, Stephens had won 14 of her last 16 matches, including defeating No. 9 Venus Williams in the semifinal. She's one of three players who have never held the No. 1 ranking who have beaten both Williams sisters in grand slam events.

Stephens now has more wins at the year's US Open matches (seven) than she had in her last six grand slam appearances combined (six).

Stephens didn't play in the US Open last year because of the foot injury.

"I should just retire now," Stephens cracked. "I told Maddie I'm never going to be able to top this. I mean, talk about a comeback."

Unranked players aside, Stephens is the second-lowest ranked player to reach and win the title match at a grand slam, after No. 111 Chris O'Neil, who won the 1978 Australian Open. She's the lowest ranked player to reach and win the title match at the US Open.

Stephens is the fourth unseeded player to reach the final in the US Open and 14th in grand slam finals in the Open Era.

Excluding when unranked Clijsters won in 2009, the matchup between No. 16 Keys and No. 83 Stephens, with a combined ranking of 99, is the lowest title match at the US Open since computerized rankings began in November 1975.

In addition to Stephens, Keys also was making a comeback from injury.

For Keys, this year's US Open was just her 10th tournament of 2017. During the off-season, Keys underwent surgery on her left wrist and missed the first two months of the year. She also, according to the WTA's website, had a second surgery on the wrist ahead of Wimbledon, and she also withdrew from Rogers Cup in Toronto because of a left forearm injury.

"If you told me two months ago that I'd be holding a (runner-up) trophy for the US Open, I'd be really happy and proud of myself," Keys said.

The No. 15 seed has never won the US Open. The last time a 15 seed won a major was Marion Bartoli at Wimbledon in 2013.

Youth movement

With this result, four different players won this year's majors -- the first time that's happened since 2014. Serena Williams won the Australian Open, Jelena Ostapenko was the French Open champion, and Garbine Muguruza hoisted the Wimbledon trophy. It's the 12th time that has happened in the Open Era.

There are also signs of a changing of the guard in women's tennis. Ostapenko, 20, became the first unseeded player and lowest ranked player to win Roland Garros in the Open Era. Muguruza, 23, became the only player to defeat both Williams sisters in a grand slam final when she defeated Venus Williams to win Wimbledon. When the rankings are released Monday, Muguruza will be in the top spot for the first time.

Stephens joins Muguruza, Ostapenko and Petra Kvitova as players born in the 1990s to win a grand slam title.

This year's US Open was the third final in the past five grand slam events not involving a player age 30 or older.